Voice coil motor and driving method thereof
AssigneeLG Innotek Co., Ltd.
InventorSANGOK PARK
Life of this patent
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Abstract
A voice coil motor (VCM) is disclosed, the VCM including: a stator including a magnet generating a first electromagnetic field; a mover including a bobbin formed with a hollow hole through which light passes and a coil formed on a periphery of the bobbin that generates a second electromagnetic field responsive to the first electromagnetic field; a base fixed at the stator and formed with an opening through which the light passes; and at least one elastic member elastically supporting the bobbin and forming a gap between the bobbin and the base when the coil is not applied with a current.
Claims24
A voice coil motor, comprising:
- a cover comprising an upper plate and a lateral plate extending from the upper plate;
- a bobbin disposed in the cover;
- a coil disposed on the bobbin;
- a magnet disposed between the coil and the lateral plate of the cover;
- a base disposed below the bobbin and coupled to the lateral plate of the cover;
- and
- a first elastic member coupled to the bobbin,
- wherein the first elastic member comprises two elastic members spaced apart from each other,
- wherein each of the two elastic members comprises an inner part coupled to the bobbin, an outer part coupled to the base, and a connection part connecting the inner part and the outer part,
- wherein the coil is electrically connected to the two elastic members,
- wherein the first elastic member is configured to support the bobbin to form a first gap between the bobbin and the base and a second gap between the bobbin and the upper plate of the cover at an initial position when no current is applied to the coil, and
- wherein the bobbin is disposed at the initial position so that the second gap is shorter than the first gap.
A voice coil motor, comprising:
- a cover comprising an upper plate and a lateral plate extending from the upper plate;
- a bobbin disposed in the cover;
- a coil disposed on the bobbin;
- a magnet disposed between the coil and the lateral plate of the cover;
- a base disposed below the bobbin and coupled to the lateral plate of the cover;
- and
- a first elastic member coupled to the bobbin,
- wherein the first elastic member comprises two elastic members spaced apart from each other,
- wherein each of the two elastic members comprises an inner part coupled to the bobbin, an outer part coupled to the base, and a connection part connecting the inner part and the outer part,
- wherein the coil is electrically connected to the two elastic members,
- wherein the first elastic member is configured to support the bobbin to form a first gap between the bobbin and the base and a second gap between the bobbin and the upper plate of the cover at an initial position when no current is applied to the coil, and
- wherein the inner part of the first elastic member is disposed at a position lower than that of the outer part of the first elastic member when the bobbin is disposed at the initial position.
A method for driving a voice coil motor, comprising:
- providing a bobbin spaced apart from a base by a first gap and from a cover by a second gap at an initial position when no current is applied to a coil;
- moving the bobbin from the initial position to a reference position by applying a backward current to the coil such that the first gap decreases;
- moving the bobbin from the reference position by reducing the backward current such that the second gap decreases;
- and
- stopping the bobbin at a position corresponding to an optimum focus.
Dependencies are inferred from the claim text.